Would turning off the disk cache speed up any pc?

I'm astonished by the speed improvements from turning off the disk cache, I think it's a useless feature now that CPU's and memory are huge.

What use do I have for a mad spinning hardisk? It doesn't enhance the exipirence at all. The web of today serves the images just as fast as a cheap disk but is much more demanding as it needs to alocate memory a thousand times and write other shit back to the disk etc. It's useless having it? I close the page, then it's gone! HA! Why keep it around anyway? Are we nuts?